This application claims priority under 35 U.S.C. §119(a) on Japanese Patent Application No. 2005-330659 filed in Japan on Nov. 15, 2005, the entire contents of which are hereby incorporated by reference.
The present technology relates to a blade cleaning jig that is applied in an image forming apparatus such as a copier, printer, or facsimile machine that forms an image by electrophotography. More specifically, the present technology relates to a blade cleaning jig that is effective for removal of toner that is affixed to a toner layer control blade, in a development apparatus in which a non-magnetic one-component developer is used.
In general, in a non-magnetic one-component developing method, regardless of whether the toner is magnetic or non-magnetic, a thin layer of one-component toner that has been charged is formed on a developer support, and with rotation of a developer roller, this thin layer is conveyed to a developing position that faces a photosensitive drum on which a latent image has been formed, and thus the latent image on the photosensitive drum is developed. In this case, the question of how to stably form a thin toner layer with uniform layer thickness and uniform charging on the developer roller is important for obtaining a good image.
In general, charging of the toner layer on this developer roller and thin layer formation are performed by a toner layer control blade that has been pressed against the developer roller with a predetermined pressure. In this toner layer charging and thin layer formation, there are cases in which toner becomes firmly adhered to the toner layer control blade due to use for a long period, so a good toner layer cannot be formed, which leads to image degradation. That is, the toner layer control blade continues to make contact with the developer roller with a predetermined pressure, and due to environmental factors or the like such as frictional heat, that pressure, or internal temperature of the apparatus, in the region where the toner layer control blade makes contact with the developer roller and the vicinity thereof, toner adheres (affixes) to the blade surface.
This affixed material, at first, is only slightly present like a thin film that has been spread on the surface, in an amount that is not particularly a problem even for image formation, but it grows with accumulated usage, and eventually has an adverse effect on images.
That is, the chargeability of the toner is worsened by the toner layer control blade due to the affixed material, and the affixed material plugs a toner inflow port between the developer roller and the toner layer control blade, or alternatively forms mechanically uneven portions in the surface that makes contact with the developer roller, leading to a decrease in toner layer thickness locally or as a whole, or local slippage (an increase in layer thickness), and it becomes impossible to form a uniform toner layer. As a result, a decrease in the density in the image, partial white streaks, or partial black streaks (in the case of a monochrome image) and the like occur.
Accordingly, in order to address these problems, development apparatuses have been proposed that clean toner affixed material on the toner layer control blade (for example, see JP S57-93370A).
The development apparatus disclosed in JP S57-93370A has a configuration in which a slidable cleaning member is provided between the developer roller and the toner layer control blade, and affixed toner is removed by sliding this cleaning member. That is, the cleaning member is configured with a thin plate member, where the front end of the cleaning member is extended to the top of the toner layer control blade, and at the rear end of the cleaning member, a tab is installed with the rear end extended outside from a groove provided in a developer container side wall. Also, the cleaning member is slidably supported and guided in the widthwise direction of the developer roller by copper wiring that has been stretched in the developer container in the center portion of the cleaning member. When foreign matter has become lodged between the toner layer control blade and the developer roller, by grasping the tab and sliding the cleaning member in the widthwise direction of the developer roller, the foreign matter is removed by the end of the cleaning member.
With the development apparatus disclosed in above JP S57-93370A, it is necessary to insure space to dispose the cleaning member inside the developer container. Also, because it is necessary to adopt a slidable structure for the cleaning member by stretching copper wiring in the development container or the like, there are the problems that the number of components increases, and the structure of the development apparatus becomes more complicated. Further, because the cleaning member is separately installed in the development apparatus, there is the problem that it cannot be applied in an existing development apparatus that does not have such a cleaning member.